German published application DE-AL No. 16 44 942 describes stable, thixotropic oil-in-water emulsions containing at least 80% by volume and preferably up to 95% by volume of non-aqueous, inner phase. The emulsifiers used for preparing these emulsions consist primarily of alkoxylation products of relatively high molecular weight alcohols, alkoxy phenols, carboxylic acids, amines, amides or polyols.
However, the production of these emulsions is relatively complicated because, at the beginning of emulsion formation, the oil to be emulsified has to be added to the aqueous, emulsifier-containing phase in small portions over a prolonged period. The full effect of the emulsifier required for forming stable emulsions is only developed at an advanced stage of the emulsion forming process. On an industrial scale, a procedure such as this is time-consuming and also expensive to implement and monitor in terms of equipment and personnel.
Accordingly, there was a need to develop an emulsifier system of which the effect is sufficient for complete emulsion formation, even when the total quantity of non-aqueous phase is added all at once to the aqueous, emulsifier-containing phase.